A urine glucose test is used to indirectly determine whether your levels of glucose, or blood sugar, are within a healthy range. It's used to monitor both type 1 and type 2 diabetes.
If your blood glucose rises above normal, your kidneys get rid of the extra glucose in your urine. That's why a urine glucose test may be able to determine whether your blood glucose is too high.
Although easier to perform than a blood test, a urine test for glucose is not as accurate as a blood test. Urine tests are usually used only when blood testing for glucose is difficult or impossible.
A health care provider may recommend a urine glucose test if you have signs of diabetes. These include increased thirst, unexplained weight loss, increased urination, tiredness, blurred vision, and sores that don't heal. Sometimes people with prediabetes or diabetes don't have any symptoms.
Your health care provider may check your glucose levels if you have risk factors for diabetes, including being overweight or obese, being physically inactive, having high blood pressure, having high cholesterol, or having a family history of diabetes. If you do not have these risk factors, but are age 45 or older, you should also be checked for diabetes at least every three years as long as your results are normal.
If you are pregnant and are at risk of developing gestational diabetes, you may be screened frequently during and for about 12 weeks after your pregnancy.
A urine glucose test may be done along with more sensitive and accurate blood tests. A urine test alone is not typically used to diagnose diabetes. Other tests that are used to diagnose diabetes or monitor blood glucose include blood glucose testing and an A1C blood test. Also, because heart health is so closely tied to diabetes, regular checks of blood pressure, cholesterol, and triglycerides are important, too.
A result for a lab test may be affected by many things, including the method the laboratory uses to do the test. If your test results are different from the normal value, you may not have a problem. To learn what the results mean for you, talk with your health care provider.
Typically, urine glucose testing involves checking the color of a test strip to see if your glucose is too high. A strip color result might range from light green (low levels) to dark brown (high levels). Depending on the results, you may have potential blood sugar problems that need more testing or management.
A health care provider will usually test your urine glucose only if a blood test cannot be done.
If you need to self-monitor urine glucose levels, your health care provider will likely give you test strips or tell you which ones to buy. Self-monitoring urine glucose levels involves holding a test strip under a stream of urine. Then, after a set amount of time, you check the color of the urine strip to figure out your glucose levels.
The test poses no known risks.
Urine glucose tests are not as accurate as blood glucose tests. Many things can cause false-positives or false-negatives. For instance, the test actually reflects what your blood glucose level was a few hours earlier, so it might not be very accurate. Other factors that can affect your reading include certain medications and vitamin C. Even the light that the test strip is checked under can lead to a false reading. Because of all these issues, a blood glucose test is done whenever possible.
You don't need to prepare for this test. Your health care provider will give you specific instructions on when to collect or test your urine and what to do before and after each collection.